Every person has the sense that he or she possesses something, that possessions (tangible or intangible) can be taken away, and that retaining possessions requires active self-defense.
If a child is not trained to (1) keep what he or she legitimately has and (2) allow others to keep what they legitimately have, then the child is training for gang life.
Parents who are immature will take away a child's possessions for their own use. Such parents also take away a child's self-development time. I have seen parents who act as if their children are nothing but built-in servants. I'm not saying that children shouldn't be made to do their fair share of helping around the house, but I am saying that the oldest shouldn't be treated as a built-in baby sitter, nor the younger ones as automatic go-fers for whoever is older. Furthermore, the child's possessions shouldn't be treated as if they belong to whichever older person wants them.
Such treatment really is training for gang life: might makes right, the strongest gets the possessions, the weaker must fulfill subservient roles and suffer unjustly harsh punishment for protesting injustices. A child raised this way, who reaches age 12 with little sense of self-achievement -- worse, with a record of school failure -- is ripe for gang involvement.